THE MEDULLA OBLONGATA AND TEGMENTUM OF THE PONS. 203 



121) that the nuclei of the posterior columns have almost dis- 

 appeared, the hypoglossal nucleus lying extended over a wide 

 area, and the huge fibrous mass of the restiform body occupying 

 a great amount of space. 



Internal to the latter appears the section of a new bundle 

 of fibres, the direct sensory cerebellar tract. It is difficult to 

 say just where it commenced; possibly as low down as the 



FIG. 121. 

 The structure of the medulla oblongata at the caudal border of the pons. 



Centr. II. B., Central tegmental tract. Dir. Sens. Cereb. B., Direct sensory cerebellar tract. 



posterior columns. It may be that this area of transversely 

 divided fibres also contains an ascending root to the acoustic 

 nerve. Fibres run from the restiform body to the inferior 

 olivary body, which latter at this level is very much diminished 

 in size. Both the fillet and the central tegmental tract appear 

 just as they did in the last section examined. Two new nuclei 

 have appeared, one, situated in the locality from which, in 

 sections farther down, the fibres of the motor vagus arose (Tig. 



